1. Field of the Invention
The present invention relates to a package for an integrated circuit.
2. Description of Related Art
Integrated circuits are typically housed within a package that is soldered to a printed circuit board. Some packages contain a heat slug to facilitate the removal of heat generated by the integrated circuit. The package may also contain a number of discrete capacitors which filter the power and/or signals provided to the integrated circuit.
FIG. 1 shows a top surface of an integrated circuit package 2 of the prior art. The package 2 has a rectangular heat slug 4 that is surrounded by a number of through hole vias 6. The vias 6 provide interconnect to a plurality of lands located on the opposite bottom surface of the package. The lands are typically soldered to an external printed circuit board. The number of lands for the package are typically limited by the number of vias 6 that can be formed in the package 2.
Mounted to the top surface of the package are a number of capacitors 8. The capacitors 8 are mounted to surface pads 10 located on the top surface. The capacitors 8 and accompanying pads are relatively large and occupy valuable space on the top of the package. Some of the vias 6 must be eliminated to provide room for the capacitors. Eliminating vias reduces the number of lands and the pin throughput of the package. Adding more capacitors to the package would necessitate the elimination of more vias and further reduce the output pins of the package. It would be desirable to provide a package design that can add capacitors without eliminating more vias and corresponding lands.
The present invention is an electronic package which has a polygonal shaped heat slug. The heat slug extends from a top surface of a package which has a plurality of vias. The package also has a number of capacitors that are mounted to the top surface. Some of the capacitors are located between the heat slug and the vias. The polygonal shape of the heat slug provides additional space on the top surface so that capacitors can be added without eliminating vias from the package.